1. Field of Invention
The invention generally relates to an air bag system installed in a motor vehicle and a diffuser used in the air bag system, and more particularly to an air bag system in which an air bag, which is stored in a folded state in a certain portion of the vehicle, is adapted to deploy by using gas supplied from an inflator via a diffuser, in order to protect a vehicle occupant or occupants.
2. Description of Related Art
In a known air bag system of the above type as disclosed in, for example, Japanese Laid-Open Patent Publication No. 11-301394, a diffuser (connecting line) having a great length is disposed in front of an inflator so as to extend in a curved form in the longitudinal direction of the vehicle. The diffuser is inserted in the air bag through a gas inlet port formed in a longitudinally end portion (i.e., rear end portion) of the air bag. The inflator supplies a gas into the air bag via gas supply ports (a large number of gas outlets) formed in the diffuser.
The diffuser of the known air bag system as described above is located ahead of the front side of the inflator that is disposed rearwardly of the air bag. With this arrangement, while gas may be guided from the inflator into the air bag with high accuracy, it is difficult to guide the gas from the inflator to inflatable chambers formed in middle and front end portions of the air bag within a sufficiently short period of time, because of relatively long distances from the inflator to the middle portion and front end portion of the air bag. It is thus difficult to complete deployment of the air bag within a sufficiently short time.
Furthermore, the known diffuser having a large length may cause various problems, such as reduced handling ease at the time of, for example, loading into a plant or installation of the air bag system in the vehicle, increased cost and weight, and increased loss of space upon installation of the system on the vehicle. The cost of the diffuser may also be increased because multiple gas outlet ports are formed in the long diffuser in different cutting processes.